One-Way Data Extraction For Logging On Airgapped Systems

November 27, 2025 by 17 Comments

If you want to protect a system from being hacked, a great way to do that is with an airgap. This term specifically refers to keeping a system off any sort of network or external connection — there is literally air in between it and other systems. Of course, this can be limiting if you want to monitor or export logs from such systems. [Nelop Systems] decided to whip up a simple workaround for this issue, creating a bespoke one-way data extraction method.

The concept is demonstrated with a pair of Raspberry Pi computers. One is hooked up to critical industrial control systems, and is airgapped to protect it against outside intruders. It’s fitted with an optocoupler, with a UART hooked up to the LED side of the device. The other side of the optocoupler is hooked up to another Raspberry Pi, which is itself on a network and handles monitoring and logging duties.

This method creates a reliable one-way transmission method from the airgapped machine to the outside world, without allowing data to flow in the other direction. Indeed, there is no direct electrical connection at all, since the data is passing through the optocoupler, which provides isolation between the two computers. Security aficionados will argue that the machine is no longer really airgapped because there is some connection between it and the outside world. Regardless, it would be hard to gain any sort of access through the one-way optocoupler connection. If you can conceive of a way that would work, drop it down in the comments.

Optocouplers are very useful things; we’ve seen them used and abused for all sorts of different applications. If you’ve found some nifty use for these simple parts, be sure to drop us a line!

Stack N’ Rack Your Hardware With The HomeRacker Project

November 27, 2025 by 2 Comments

Things are cooler when rack-mounted, and [KellerLab] aims to make that all far more accessible with the HomeRacker, a modular and 3D-printable rack building system designed to let you rack-mount to your heart’s content. While it can handle big things, it seems especially applicable to tasks like mounting one’s home network equipment and Raspberry Pi machines.

A rack is a great place for those Raspberry Pi servers and home networking equipment, but it can also handle bigger jobs.

The basic system (or core) consists of three different parts: supports, connectors, and lock pins. The supports are the main structural bars, the connectors mostly go at the corners, and the lock pins ensure everything stays put. The nominal sizing is a 15 mm x 15 mm profile for the supports, with lengths being a multiple of 15 mm.

All is designed with 3D printing in mind, and requires no tools to assemble or disassemble. There are design elements we really appreciate, like how parts are printed at an angle, which improves strength while eliminating the need for supports. The lock pins (and the slots into which they go) are designed so that they are effective and will neither rattle nor fall out.

But the core system is just the foundation. There’s plenty of modularity and expansions to handle whatever one may need, from Gridfinity shelves and drawers to various faceplates and other modules. There are some example applications available from [KellerLab]’s HomeRacker models page, like CD shelf, under-desk drawer, or filament rack.

[KellerLab] welcomes any collaboration, so check out the GitHub repository for CAD references and design files.

One last point to make about the value of printing objects like this at an angle: not only can the resulting layer lines provide better strength and reduce or eliminate the need for supports, but printing at an angle can help hide layer lines.

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Google Is Building A New OS

November 27, 2025 by 33 Comments

Windows, macOS, and Linux are the three major desktop OSs in today’s world. However, there could soon be a new contender, with Google stepping up to the plate (via The Verge).

You’ve probably used Google’s operating systems before. Android holds a dominant market share in the smartphone space, and ChromeOS is readily available on a large range of notebooks intended for lightweight tasks. Going forward, it appears Google aims to leverage its experience with these products and merge them into something new under the working title of “Aluminium OS.”

The news comes to us via a job listing, which sought a Senior Product Manager to work on a “new Aluminium, Android-based, operating system.” The hint is in the name—with speculation that the -ium part of Aluminium indicates its relationship to Chromium, the open-source version of Chrome. The listing also indicated that the new OS would have “Artificial Intelligence (AI) at the core.” At this stage, it appears Google will target everything from cheaper entry level hardware to mid-market and premium machines.

It’s early days yet, and there’s no word as to when Google might speak more officiously on the topic of its new operating system. It’s a big move from one of the largest tech companies out there. Even still, it will be a tall order for Google to knock off the stalwart offerings from Microsoft and Apple in any meaningful way. Meanwhile, if you’ve got secret knowledge of the project and they forget to make you sign an NDA, don’t hesitate to reach out!

Phone-grabbing robot

This Bedtime Bot Enforces Better Sleep Hygiene

November 27, 2025 by 5 Comments

[Will Dana] is engineering his way to better sleep hygiene. Not satisfied with a simple bedtime reminder notification — such things are easily dismissed, after all — [Will] is offloading self-control onto a robot which will take his phone away at bedtime.

Scrolling in bed is allowed up to a prescribed time. At that time, a rack and pinion-mounted arm rises up from behind his mattress, presenting an open hand, ready to accept the object of his addiction. At this point, a countdown begins. If he does not hand over the device in a matter of seconds, the robot escalates by flashing obnoxiously bright lights in his face.

The nocturnal technology detox is not absolute, however. A button allows [Will] to temporarily retrieve his phone after it has been confiscated. This safety override accounts for the Inevitable situation where he will need to send a last-minute text before nodding off. The flashing light disincentive countdown is restarted upon retrieval, ensuring that [Will] does not cheat his own system for additional scroll time.

As a brief sidebar, [Will] does a nice job explaining how pulse-width modulation works for the purpose of controlling the speed of the rack and pinion mechanism.

For more of [Will’s] projects see this iPad suspension system a Lamp that tracks the location of the ISS and a drum that uses the piezoelectric effect to charge mobile devices.

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KiDoom Brings Classic Shooter To KiCad

November 26, 2025 by 8 Comments

As the saying goes: if it has a processor and a display, it can run DOOM. The corollary here is that if some software displays things, someone will figure out a way to make it render the iconic shooter. Case in point KiDoom by [Mike Ayles], which happily renders DOOM in KiCad at a sedate 10 to 25 frames per second as you blast away at your PCB routing demons.

Obviously, the game isn’t running directly in KiCad, but it does use the doomgeneric DOOM engine in a separate process, with KiCad’s PCB editor handling the rendering. As noted by [Mike], he could have used a Python version of DOOM to target KiCad’s Python API, but that’s left as an exercise for the reader.

Rather than having the engine render directly to a display, [Mike] wrote code to extract the position of sprites and wall segments, which is then sent to KiCad via its Python interface, updating the view and refreshing the ‘PCB’. Controls are as usual, though you’ll be looking at QFP-64 package footprints for enemies, SOIC-8 for decorations and SOT-23-3 packages for health, ammo and keys.

If you’re itching to give it a try, the GitHub project can be found right here. Maybe it’ll bring some relief after a particularly frustrating PCB routing session.

A Friendly Reminder That Your Unpowered SSDs Are Probably Losing Data

November 26, 2025 by 30 Comments

Save a bunch of files on a good ol’ magnetic hard drive, leave it in a box, and they’ll probably still be there a couple of decades later. The lubricants might have all solidified and the heads jammed in place, but if you can get things moving, you’ll still have your data. As explained over at [XDA Developers], though, SSDs can’t really offer the same longevity.

It all comes down to power. SSDs are considered non-volatile storage—in that they hold on to data even when power is removed. However, they can only do so for a rather limited amount of time. This is because of the way NAND flash storage works. It involves trapping a charge in a floating gate transistor to store a single bit of data. You can power down an SSD, and the trapped charge in all the NAND flash transistors will happily stay put. But over longer periods of time, from months to years, that charge can leak out. When this happens, data is lost.

Depending on your particular SSD, and the variety of NAND flash it uses (TLC, QLC, etc), the safe storage time may be anywhere from a few months to a few years. The process takes place faster at higher temperatures, too, so if you store your drives in a warm area, you could see surprisingly rapid loss.

Ultimately, it’s worth checking your drive specs and planning accordingly. Going on a two-week holiday? Your PC will probably be just fine switched off. Going to prison for three to five years with only a slim chance of parole? Maybe back up to a hard drive first, or have your cousin switch your machine on now and then for safety’s sake.

On a vaguely related note, we’ve even seen SSDs that can self-destruct on purpose. If you’ve got the low down on other neat solid-state stories, don’t hesitate to notify the tipsline.

Benchmarking Chinese CPUs

November 26, 2025 by 13 Comments

When it comes to PCs, Westerners are most most familiar with x86/x64 processors from Intel and AMD, with Apple Silicon taking up a significant market share, too. However, in China, a relatively new CPU architecture is on the rise. A fabless semiconductor company called Loongson has been producing chips with its LoongArch architecture since 2021. These chips remain rare outside China, but some in the West have been benchmarking them.

[Daniel Lemire] has recently blogged about the performance of the Loongson 3A6000, which debuted in late 2023. The chip was put through a range of simple benchmarking tests, involving float processing and string transcoding operations. [Daniel] compared it to the Intel Xeon Gold 6338 from 2021, noting the Intel chip pretty much performed better across the board. No surprise given its extra clock rate. Meanwhile, the gang over at [Chips and Cheese] ran even more exhaustive tests on the same chip last year. The Loongson was put through typical tasks like  compressing archives and encoding video. The outlet came to the conclusion that the chip was a little weaker than older CPUs like AMD’s Zen 2 line and Intel’s 10th generation Core chips. It’s also limited as a four-core chip compared to modern Intel and AMD lines that often start at 6 cores as a minimum.

If you find yourself interested in Loongson’s product, don’t get too excited. They’re not exactly easy to lay your hands on outside of China, and even the company’s own website is difficult to access from beyond those shores. You might try reaching out to Loongson-oriented online communities if you seek such hardware.

Different CPU architectures have perhaps never been more relevant, particularly as we see the x86 stalwarts doing battle with the rise of desktop and laptop ARM processors. If you’ve found something interesting regarding another obscure kind of CPU, don’t hesitate to let the tipsline know!